This invention relates to a separate lubricating system for an outboard motor and more particularly to an improved construction for insuring adequate lubrication for a two-cycle engine.
The lubrication of two-cycle engines presents certain difficulties. Although it has been the conventional practice to mix the lubricant with the fuel, such an arrangement is obviously inconvenient. Furthermore, there is always the danger that an operator will attempt to run the engine on fuel which has not had lubricant added to it, thus damaging the critical components of the engine. It has been, therefore, proposed to provide a separate lubricating system wherein lubricant is delivered from a lubricant pump to the components of the engine to be lubricated. If the engine has multiple cylinders, the use of such separate lubricating systems requires a complex pump with plural discharges amd can add to the size, weight and complexity of the engine.
In an alternative arrangement, it has been proposed to provide a separate lubricating system wherein the lubricant is delivered into the fuel system under pressure by a pump for mixing before induction into the engine. However, where the engine has multipile cylinders and multiple carburetors barrels, this arrangement may not provide uniform lubrication between the various cylinders of the engine.
It is, therefore, a principal object of this invention to provide an improved lubricating system for two-cycle engines.
It is another object of this invention to provide a lubricating system for two-cycle engines wherein lubricant is mixed with the fuel before the fuel is delivered to the carburetor or carburetors of the engine.
In outboard motors, it is a normal practice to employ a two-cycle engine. In addition to the aforenoted lubricating problems, the use of two-cycle engines as outboard motors presents certain challenges toward lubricating the engine. It is desirable to provide a separate lubricating system for outboard motors to achieve the results aforenoted. However, it is difficult to provide the adequate oil supply for long term running within the cowling of the motor. It has, therefore, been proposed to provide a small delivery tank that is contained within the motor and which is supplied from a larger storage tank positioned within the hull of the boat. An arrangement has been provided for insuring an adequate level of lubricant in the delivery tank. However, the motor is subjected to considerable forces when making turns, starting and stopping. The float operated devices heretofore used for maintaining adequate lubricant in the small delivery tank have been sensitive to such changes in direction or speed of travel and can result in malfunctioning under these conditions.
It is, therefore, a further object of this invention to provide an improved lubricating system for an outboard motor.
It is another object of this invention to provide a separate lubricating system for an outboard motor that is not sensitive to changes in speed or direction of travel.